1. Field of the Invention
This invention relates to a method and apparatus for communicating electronic data. Specifically, communication equipment using different data and command exchange protocols are linked in a redundant networking environment.
1. Description of the Prior Art
As computer technology has increased in complexity and usage, computer networks have incorporated a wide range of applications. Computer networks are used in all types of businesses, industries and institutions. However, in a computer network employing communications equipment, the network must be configured such that each of the respective processors may communicate with one another. Several different communications protocols could be involved. Therefore, a need exists to allow each transmitting device to send and receive data and commands in not only its own unique protocol, but also in the protocol used by the receiving device. Such a requirement creates the need for an interface that converts from one protocol to a second, different protocol.
Because of the critical nature of communications between devices in certain applications, such as in the communications industry, it is often necessary to provide for redundant connections to ensure communications will continue in the event that one communications path fails. A redundant communications path provides a safeguard against path failure of the primary communications path. It is therefore desirable to provide a protocol converting interface with the ability to provide a redundant communications path.
FIG. 1 shows the current state of the art and illustrates the problems the present invention overcomes. Existing connecting means between communications equipment has several limitations. FIG. 1 illustrates a reliance on using available hardware to link, for instance, a Lucent Technologies 5ESS.RTM. Switch described in U.S. Pat. No. 4,592,048 issued to Beckner et al. on May 27, 1986 and in AT&T Technical Journal, Vol. 64, No. 6, Part 2, pp. 1305-1564 or other similar switching system and a peripherial device, such as a Sun.RTM. workstation. If a manufacturer went out of business or some components were no longer manufactured, there would be no available means to create the link.
Referring again to FIG. 1, currently only specific Administrative Service Modules (ASM's) 14 can be connected to a switching system. The use of Dual Serial Channel (DSCH) cabling 20 limits the number of peripherial devices that can be connected to the switching system to an ASM 14 that can connect to the DSCH cable 20. It is desirable to connect other peripherial devices, such as workstations, dumb terminals, personal computers (PC's) or communications modules (CM's), to the switching system other than specific ASM's. This connection would create configuration flexibility, providing a larger number of peripherial devices to be used with the switching system. The resultant flexibility will support increased call capacity, increased revenue, and lower costs.
FIG. 1 illustrates the use of DSCH cabling 20 to connect between the switching system and the peripherial device. Use of DSCH cabling 20 limits the length of the link between communications equipment to a maximum 100 feet between the switching system and the peripheral device. Therefore, distance constraints limit where peripheral devices may be located, usually requiring the peripheral device to reside within the room containing the switching system. The Network Equipment Building System (NEBS) Bellcore standard for generic equipment requires equipment within the room containing the switching system to meet certain constraints. Because NEBS compliant peripherals are more costly, removing the peripheral device from the switching room will reduce costs while at the same time adding flexibility.
It is an object of the invention to provide a method and apparatus to enable communication between a series of networked communications equipment, each potentially using a different data and command exchange protocol and providing a redundant data path in the event of primary path failure. The invention allows a larger number of different types of peripheral devices to be used with switching systems that employ DSCH cabling 20, providing increased call capacity, increased revenue, and lower overall costs.